Denis Shapovalov performed almost flawlessly behind the microphone. If only he hadn’t been so totally boneheaded moronic on the tennis court a half-hour earlier.

A left-hander talented enough to have both won a Wimbledon junior men’s title and earned selection to Canada’s Davis Cup team, the 17-year-old from Richmond Hill, Ont., morphed into a spoiled brat with a display of pique that resulted in a default in the deciding rubber against Great Britain’s Kyle Edmund on Sunday.

Edmund had broken Shapovalov’s serve in each of the first two sets and he broke through again in the third game of the third set. Shapovalov, standing near the service line on his side of the net, then ripped an all-world forehand smash with the remaining tennis ball in his right hand.

He was undoubtedly trying to whack it into the upper reaches of the seats at TD Place arena, but instead the ball struck chair umpire Arnaud Gabas of France in the eye.

The rules were clear. Such a mind-numbingly humongous breach of tennis etiquette warranted immediate default, not only handing the match to Edmund — it read 6-3, 6-4, 2-1 (default) on the scoresheet — but also handing the tie to the British, who will now travel to France for a World Group quarterfinal in April.

Canada must now return to World Group playoffs in September in its bid to remain in the top section of the annual international team competition for men’s professional tennis.

The question of whether Shapovalov should be part of that delegation was one that Canadian Davis Cup captain Martin Laurendeau wasn’t prepared to answer fully on Sunday evening.

In fairness, selections for that playoff round should be and undoubtedly will be based on who’s healthy and available. Perhaps world No. 4 Milos Raonic of Thornhill, Ont., who begged off from this first-round tie against Britain because of injury, will be ready again. Certainly there should be room for Vancouver’s Vasek Pospisil, who gave a gritty, inspired performance in defeating Britain’s Dan Evans 7-6 (3), 6-4, 3-6, 7-6 (5) in the earlier Sunday singles match to even the tie at two points apiece.

“It’s a lesson that (Shapovalov) will take from this and move forward. He’s a kid, as you see,” Laurendeau said. “He wants to face the music, he’s not going to shy away. … He’s not that kind of guy. He’s a great talent.

“It’s just the beginning of his career, so he’ll draw a big lesson out of this. Curbing your emotions on the court is probably, anyway, something that he’ll need to do to make a living in this sport.”.

Shapovalov sat down behind a microphone in the interview area, pressed a button to activate it, and started speaking. He began by stating that he had gone back to Gabas and apologized again for his actions.

“Luckily he’s OK, but, obviously, it was just unacceptable behaviour from me,” Shapovalov said. “To be honest, I feel just incredibly ashamed and embarrassed, and I just feel awful for letting my team down, for letting my country down, for acting in a way I would never want to act.

“I can promise you that that’s the last time I will do anything like that. I’m going to learn from this and try to move past it.”

The default of Shapovalov put a sour ending on what had been a sweet day for tennis in general and Canadian tennis in particular. Pospisil, who had played not only a winning singles match against Edmund on Friday, but also a losing doubles match with Toronto’s Daniel Nestor against Britain’s Jamie Murray and Dominic Inglot on Saturday, dug deep as could be and found a way past Evans.

“I thought Kyle was absolutely terrific,” British captain Leon Smith said. “He completely bossed the match. It was pretty much one-way traffic and it would have been nice for Kyle to go over the line in a straight-sets win, which it was heading for, and a great performance.

“But, to finish like that. … I feel sorry for Denis. He has learned a harsh lesson (Sunday). It’s a shame. It’s a shame for the fans that were there. It’s a shame it happened, but he’ll learn, I’m sure.”

The visitors had come into the day with a 2-1 lead. Evans and Pospisi had defeated Shapovalov and Edmund, respectively, on Friday before Murray and Inglot downed Pospisil and Nestor in Saturday doubles.

Sunday’s crowd of 7,497 lifted the three-day total to 21,482, highest ever for a Davis Cup tie hosted in Canada. The previous best was 17,805 for a matchup with Spain at Vancouver in February 2013.

Those spectators, including several dozen boisterous British supporters, had the arena rocking during the Pospisil-Evans match, but the air was starting to leak as Edmund extended his lead over Shapovalov and went out of the place completely with the awkward, sudden ending.

“It’s disappointing for everyone,” Laurendeau said. “Obviously, there was a lot of emotion here in the arena. That (finish) surprised me. I’ve never seen that before. … It’s important to get back at it and face the music.”.

POSPISIL DID HIS PART

It had been, Vasek Pospisil finally admitted, 50-50 whether he would even take the court for Canada’s Davis Cup team on Sunday.

The 26-year-old from Vancouver battled through knee, quad and back problems to win a Friday singles match and to play four sets in a losing doubles match on Saturday, but it only a night of “aggressive” treatment and rest that Pospisil decided he could step on the court against Britain’s Dan Evans.

“If I had woken up the way I had woken up (Saturday), I wouldn’t have played, 100%” Pospisil said after his 7-6 (3), 6-4, 3-6, 7-6 (5) victory extended the World Group first-round tie at TD Place arena. “The concern was whether my knee would hold hurt in the fourth, fifth set like it did a little bit in the doubles (Saturday). It kind of came on late in the match and my serve vanished.

“So, it was kind of a risk that we took, but, because I felt good, it was a little bit more of a calculated risk. I had a really good treatment (Saturday) night and I reacted well.”

Evans gave credit to his adversary for a battle waged well.

“I felt in the match all the time,” said Evans, who allowed that he had been experiencing some discomfort in his feet. “But, when he was behind, he was serving so well. I don’t even know how many break points I had, and my conversion rate must have been just diabolical. I’ve got to give it to him. He played better than me today.”

Both men were thinking about some well-earned rest.

Pospisil said he would fly to San Francisco on Monday as scheduled, but sounded Sunday like a man more interested in looking at the Golden Gate Bridge than playing in the scheduled ATP Challenger Tour event.